Precious gems around the world

910-carat found in southern African kingdom

A 910-carat colorless diamond found at the Letseng mine in the southern African kingdom of Lesotho, Jan. 15, 2018. Full Story

Gem Diamonds/Handout via Reuters

910-carat found in southern African kingdom

A 910-carat colorless diamond found at the Letseng mine in the southern African kingdom of Lesotho, Jan. 15, 2018. <a href="http://abcnews.go.com/US/910-carat-colorless-diamond-found-lesotho/story?id=52356102"target="external"> Full Story</a>

Gem Diamonds/Handout via Reuters

Costume jewelry turns out to be a real diamond

An image issued by auction house Sotheby's, on May 22, 2017, of a large 26.27 karat diamond ring, "costume jewelry" diamond really worth hundreds of thousands. Thirty years ago on what was thought to be a piece of costume jewelry, turned out to be a 26.27 carat white diamond. The gem was bought at a car boot sale in the U.K. and is expected to fetch about $454,000 when it is auctioned by Sotheby's next month.

Sotheby's via AP Photo

Most valuable cut diamond, the "Pink Star"

The "Pink Star" diamond, the most valuable cut diamond ever offered at auction, is displayed by a model at a Sotheby's auction room in Hong Kong. The stunning 59.6 carat diamond sold for $71.2 million, setting a record for any diamond or jewel.

Vincent Yu/AP

Rare 887-carat emerald up for auction

This is the 887-carat "La Gloria," a rare emerald that is part of a larger collection of rare gems and will be up for auction in April. The gem has what is called, "a small surface calcite matrix" which helps to identify it coming from the Muzo mine in Columbia.

Photos courtesy of Guernsey's

One of the largest uncut diamonds discovered in Sierra Leone's Kono district.

A diamond believed to weigh over 700 carats in size is held by Sierra Leone's President Ernest Bai Koroma in the presidential office in Freetown, Sierra Leone, March 16, 2017. It was discovered by a minister who turned it over to the government, saying he hopes it helps to boost recent development in his impoverished nation.

AP Photo

World's Most Expensive Rough Diamond on Display

Jewelry company de Grisogono displays the Constellation rough diamond, measuring over 6 centimeters wide during a news conference in Paris, Sept. 9, 2016. De Grisogono purchased the rock for $63 million. The Constellation weighs 813 carats and was discovered by Canadian company, Lucara Diamond, at its Karowe mine in Botswana in November 2015.

Charles Platiau/Reuters

A Rare Fancy Vivid Blue Diamond

During a press preview by Christies's auction house it shows the 'Oppenheimer Blue,' a rare fancy vivid blue diamond weighing 14.62 carat is seen in Geneva, May 12, 2016.

Fabrice Coffrini/AFP/Getty Images

Tennis Ball Sized Diamond Could Fetch More Than $70 Million

A Sotheby's employee holds Lesedi La Rona Diamond on May 3, 2016 in New York. The diamond, which is the size of a tennis ball, 1,109 carats, is the largest discovered in more than a century and could sell at auction for more than $70 million. Sotheby's says it will offer the Lesedi la Rona diamond in London on June 29.

Donald Bowers/Getty Images for Sotheby's/AP

Sotheby's Unveils 100-Carat Diamond

An employee holds a 100-carat perfect diamond at Sotheby's auction house, Feb. 13, 2015, in London. Forming part of the Magnificent Jewels sale in New York, April 21, 2015, it is expected to fetch between $19-25 million.

Carl Court/Getty Images

8.41-Carat Pink Diamond Sells for Record $17.77M

<p>
Sotheby's Hong Kong sold an 8.41-carat pear-shape &quot;internally flawless fancy vivid&quot; purple-pink diamond as part of the Magnificent Jewels and Jadeite Autumn Sale 2014 on Oct. 7, 2014 at the Hong Kong Convention and Exhibition Center. The gem, estimated to be worth $12.8 to $15.4 million, sold for a record $17.77 million. The auction house also achieved the world auction record price per carat for any sapphire ($236,404 per carat) when a 17.16-carat Kashmir sapphire and diamond ring sold for $4.06 million.&nbsp;</p>

Sotheby's Hong Kong

Four Rare Fancy Red Diamonds

<p>
Four rare red diamonds from the 2014 Rio Tinto Diamonds Tender collection were up for auction until October 8, 2014. The largest of the four &quot;Fancy Red&quot; diamonds is the Argyle Cardinal, second left, a radiant cut 1.21 carat diamond named after the small North American bird. The Argyle Cardinal was sold for an undisclosed amount.&nbsp;</p>

Rio Tinto

'Exceptional' 122.5 Carat Blue Diamond Unearthed

A rare 122.5 carat blue diamond, which could be the most valuable ever found, has been unearthed at Cullinan mine in South Africa. The mine is owned by a London-based company Petra Diamonds Limited. In the photo, CEO Johan Dippenaar holds the "exceptional" blue diamond recovered in June 2014. On June 13, 2014, Petra said in a statement that it is evaluating the diamond. The highest price on record paid for a rough diamond was about $35.3 million in February 2010 for a 507 carat white stone, also recovered from Cullinan, according to the Telegraph.

Petra Diamonds

Christie's Auctions 'The Blue'

Christie's auctioned a 13.22 carat, pear-shaped blue diamond for $24 million in Geneva, Switzerland, on May 14, 2014. Called "The Blue," it is the largest flawless fancy vivid blue diamond to ever appear at auction. The previous record for a vivid blue diamond was the $15.7 million BVLGARI Blue, a two-stone fancy vivid blue triangular-cut diamond of 10.95 and 9.87 carats sold through Christie's New York in Oct. 2010. Swiss watchmaker Swatch, which bought Harry Winston last year, is renaming the diamond The Winston Blue. "When Christie’s announced they were offering the largest flawless fancy-vivid blue the [Gemological Institute of America] had ever graded, I had to buy it," Harry Winston CEO Nayla Hayek said in a statement.

Christie's

100-Carat Yellow Diamond

A Sotheby's employee shows The Graff Vivid Yellow at 100.09 carats, one of the rarest yellow diamonds of its size, which was sold for about $16 million at auction in Geneva, Switzerland, May 13, 2014.

Martial Trezzini/Keystone/AP Photo

$55 Million Watch

Graff Diamonds unveils the $55 million "Hallucination" watch made of 110 carats of rare multi-colored diamonds. It was introduced at the 2014 Baselworld watch and jewelry fair and is for sale.